U.S. Pat. No. Re. 29,319 discloses a drainage system for draining fluids from a wound while at the same time permitting observation of and access to that wound. A commercially-available version of such a system is also shown and described in a technical bulletin entitled "Hollister Draining-Wound Management System," published by Hollister Incorporated, Libertyville, Illinois. Such a system includes a drainable pouch having an apertured wall provided with an annular adhesive patch for securing the pouch to a patient in an area surrounding the wound site. The opposite wall of the pouch is provided with an access opening, and a transparent cap is adhesively secured to the pouch about that opening. When access to the wound is required for surgical examination, drain adjustment, wound treatment, or any other reason, the pressure-sensitive adhesive seal between the cap and pouch is broken and the cap is temporarily removed.
The adhesive attachment of the access cap to the pouch is generally effective but is subject to three inherent shortcomings. If reclosure is desired, care must be exercised to avoid contacting the adhesive surfaces with any liquids. Such avoidance may be difficult because of drainage fluids that have passed through the pouch leaving residual amounts clinging to the inner surfaces of the pouch and cap in the vicinity of the adhesive seal. Secondly, a surgeon, nurse, or other attendant must be careful in replacing the cap to avoid pressing the cap firmly against the wall of the bag overlying or surrounding the wound site since even moderate pressure may cause intense pain to the patient. The exercise of judgment is required because limited pressure is necessary in order to adhesively reseal the cap; if too little force is applied, an imperfect seal may be formed and leakage may result. Third, there is always a risk that following its removal, such a cap may be temporarily misplaced or even dropped, resulting in contamination of the cap and necessitating its replacement by a fresh cap which may not always be readily available.
While mechanical seals between ribbed plastic parts are known and have been used for ostomy appliances, such mechanical seals have not been considered suitable for draining wound management systems because of the forces required to join the ribbed sealing elements. Such forces are considerably greater than those needed to create a pressure-sensitive adhesive seal and, hence, would be even more objectionable if applied to the immediate vicinity of the wound. Therefore, although the adhesive mounting of an access cap is not without some objections, no satisfactory substitute for use in a draining wound system has heretofore been known.
This invention is therefore concerned with a wound drainage system having an access cap that is capable of being positively and effectively resealed despite the presence of liquid along the sealing surfaces, and that may be easily and quickly resealed without applying any pressure to the patient in the area of the wound. A further object is to provide a device having sealing means for the access cap that is capable of repeated opening and closing of the cap without deterioration in sealing effectiveness. A still further object is to provide a wound drainage device having an access cap with mechanical sealing means operated by squeezing together the cap and a flanged ring provided by the pouch about its access opening, such squeezing force being applied by the fingers of each hand without the application or transmission of forces to the wound area. It is also an object to provide a pouch that allows and facilitates the closure of an access cap by the application of such squeezing forces without risk of injury or discomfort to the patient. An additional object is to provide an access cap that is permanently attached to the pouch so that it remains readily available when in open position, is less likely to become contaminated because it cannot be misplaced or dropped, and tends to be guided by its connecting straps into a position for resealing when closure is desired.
Briefly, the wound drainage device takes the form of a pouch of flexible fluid (liquid and odor) impermeable plastic film having top, bottom, and side walls, the side walls being accordion-pleated and providing low resistance to unfolding when the top wall is lifted away from the bottom wall. In the embodiment illustrated, the bottom wall has an enlarged aperture with a flexible barrier panel of gas-permeable liquid-resistant material sealed across the aperture and projecting outwardly therefrom. The barrier panel has pressure-sensitive adhesive along its undersurface so that the panel may be secured to a patient about the wound site after the doctor, nurse, or attendant has cut an opening in the panel conforming generally with the outline of the wound.
The top wall of the pouch is provided with an access opening in general alignment with the enlarged aperture in the bottom wall. A flat plastic ring having a flanged periphery is secured to the top wall about the opening and is provided with a series of circumferential ribs projecting upwardly from the flange thereof. A closure cap is provided with a flat plastic rim having depending circumferential ribs capable of releasably and sealingly interlocking with the upstanding ribs of the ring when the rim and ring are squeezed together.
To seal the cap in place, the user first lifts the flanged ring of the pouch's top wall an inch or two above the wound area, such lifting operation causing a partial unfolding of the pleated side walls of the pouch. Because of such pleated construction and flexibility of the plastic film from which the pouch is formed, such a lifting operation may be carried out without transmitting any appreciable forces to the patient in the vicinity of the wound. With the flanged ring thus raised above and wound site, the user simply urges the thin flexible rim of the closure into mechanical sealing engagement with the flanged ring.
The flatness of the ring and closure rim, the arrangement of concentric locking ribs and grooves, and the flexibility or bendability of the plastic material from which such parts are made all contribute towards providing a highly-effective liquid-tight closure that can be easily and repeatedly opened and resealed and yet, at the same time, is highly resistant to unintentional or accidental opening. The interlock is capable of withstanding distortions caused by expansion of the pouch as it is filled, or by any other forces generated during normal use of the drainage device, without risk of separation and leakage. Tabs projecting from the peripheral edges of the ring and rim may be easily gripped and urged apart to initiate opening of the closure and, when fully opened, the cap nevertheless remains connected to the flanged ring of the pouch by means of integrally-formed connecting straps extending between the two.
Other features, objects, and advantages of the invention will become apparent from the specification and drawings.